Up until now, a film having a peel off backing layer could not be used for hydrographic printing because the plurality of ink droplets deposited onto the film during the printing process could not be dried fast enough to produce a stable and distinct image. Instead, the ink droplets would tend to pool and/or run on the surface of the film and create smudges, smears and blurs which would render the film unusable. Normally, a film having a backing layer is easier to handle than a film without a backing layer. In addition, a film having a backing layer can be rolled up on a supply roll and therefore is usually easier to store than a film without a backing layer. Those practicing hydrographic printing are asking for printed soluble films having a backing layer.
In the hydrographic printing process, the film is usually water soluble. The film can also be made from a biodegradable material. Polyvinyl acetate (PVA) and corn starch are the two most widely used materials to make a hydrographic film. After the soluble film is printed, it stored, usually in sheet form, until it is ready to be used. In starting the hydrographic process, a tank of water is usually heated to an elevated temperature, from between about 60° to about 100°. The soluble film is then placed on the surface of the water such that the film floats on the surface but is totally wetted by the water. An activating agent, such as a detergent or similar chemical, can be used to enhance the printing process. An object is then slowly lowered into the tank of water through the film, at an angle of about 25 to about 70 degrees. This action causes the image printed on the film to be transferred onto the outer surface of the object. In the hydrographic printing process, the water bath is used to biodegrade the soluble film, and the printed image becomes permanently secured to the outer surface of the object in a matter of seconds.
Now a printer has been invented that can print a soluble film which has a peel off backing layer.
In addition, improvements in films have now led to a number of new films which do not have a separate peel off backing layer but instead incorporate a soluble backing material onto the film itself. After these new films are printed, the image on the printed film can be transferred onto the outer surface of an object using the hydrographic printing process. In the hydrographic process, the printed film is again placed on the upper surface of an aqueous solution, such as water. The aqueous solution will cause the soluble backing material to dissolve before an object is dipped through the printed film. Once the film has been applied to the object, the object is removed from the aqueous solution, it is rinsed off and then is allowed to dry. The aqueous solution is used to dissolve the film leaving the printed image permanently attached to the outer surface of the object.
Now, a printer has been invented that can print a soluble film having a backing material incorporated onto the film itself.